Background and Aim: Arsenic (As) compounds are environmental toxicants which are among human carcinogens. Sodium arsenite exposure leads to its accumulation in the liver resulting in liver disorders. The aim of this study was to investigate the protective effect of curcumin, as an antioxidant, on the liver tissue in the mice exposed to sodium arsenite.

Material and Methods: Thirty NMRI mice with mean body weight of 31±2 g. were randomly divided into 5 groups: control, scheme (receivingDMSO),curcumin (15mg/kg/day), sodium arsenite (5mg/kg/day) and sodium arsenite+curcumin groups.Every groupconsisted of 6 mice. The exposure was by intraperitoneal injections and carried out for 5 weeks. Then the mice were killed and the liver tissue was removed and weighed. Histopathological and stereological analyses were performed and the incidence of hepatocyte cells apoptosis (by the TUNEL method) was determined. Data were analyzed using one way ANOVA, and the differences among mean values were considered significant at P<0.05.

Results:A significant increase in the mean relative weight of liver, total volume of sinusoids, bile ductules (p<0.001) and total number of hepatocytes (p<0.03) and a significant decrease in the total volume of the central veins (p<0.001), the mean volume of the hepatocytes (p<0.04) and their nuclei (p<0.001) were observed in sodium arsenite group compared to those in control and scheme groups. Histopathological examination also revealed parenchymaldisorganization, inflammatory cell infiltration, necrosis of hepatocytes and destruction of reticulin fiber scaffold in the mice liver treated with sodium arsenite. Most of sodium arsenite-induced liver damage improved in the sodium arsenite + curcumin group to the same extent as control group (p<0.05).